Electrical synchronizing device



Dec 18, 1934. R BARTHELEMY I 1,985,139

ELECTRICAL SYNCHRL ONI ZING DEVICE Filed Jan. 23, 1931 Patented Dec. 18, 1934 UNITED STATES PATENT OFFICE 1,9s5,1a9 ELECTRICAL SYNCHRONIZING DEVICE Ren Barthelemy, Fontenay-aux-Roses, France, assignor to Compagnie pour la Fabrication des Compteurs et Materiel dUsines a Gal,

Montrouge, France Application January 23, 1931, Serial No. 510,815 In France February 3, 1930 4 Claims.

6 dies down at the end of a certain time.

In practice, the oscillator is constituted by a lamp filled with neon or other gas and the operating characteristics of whichapproximate to those of a relaxation oscillator.

The principal drawback encountered in applying this method is that the time of discharge of the condenser into the gas tube varies and is not constant for each oscillation.

The present invention has reference to a method of accurately limiting the duration of the oscillation set up, or even if there be no oscillation, of destroying the electrical conditions which would be permanently established after the emission of the synchronizing top. This method consists either in emitting a second top oi opposite effect to the first, or in the production of a local oscillation at the receiving end, controlled by the rotation of the motor to be synchronized and which brings the oscillator, the gas tube in the case in point, back to its initial state.

With these and other objects in view, the invention is characterized by the arrangement and combination of parts hereinafter described.

Several embodiments of theinvention have been disclosed in the accompanying drawing wherein:

Fig. 1 illustrates means for controlling the oscillations of the gas filled tube.

Fig. 2 illustrates a modification in which the oscillations are controlled by the rotation of the motor to be synchronized.

In the embodiment of Fig. l which is given purely by way of example without restricting the scope of the invention, N is a neon tube to which is applied the voltage of the source U, the magnitude of such voltage lying between the lighting voltage and the extinguishing voltage of the tube. A transformer T supplies a brief electromotive force in a suitable direction in the circuit of the tube. Said transformer will be generally fed by the current supplied by a receiving amplifier of high frequency waves not illustrated in the figure. Under the effect of the first signal emitted, the tube lights up and a current I flows through the res'istance'R, mounted in the tube circuit. The oscillations of the potential RI across the resistance R are applied to the: winding W of the motor to "be'synchronized, generally through the medium of a suitable amplifier L on which a condenser C impresses the variations of potential RI set up at the ends of the resistance R by the current I discharged by the tube N. A second signal of opposite sign is then emitted and produces in the transformer a short oscillation of contrary sign to the first and the tube is extinguished. The current I stops flowing. It will thus. be understood that the duration of the. flow of the current I is determined solely by the signals with all the desired accuracy.

Fig. 2 illustrates a modification according to which the transformer T includes an additional winding T adapted to be fed with current from a source E in the circuit of which is included a commutator F mounted on the shaft of the motor to be synchronized W.

Matters are arranged so that when the signal for lighting up the tube N is emitted, the commutator opens the circuit of the winding T, so that no current flows through it. When the signal ceases, the commutator F has been rotated into the position in which it closes the circuit of the winding T so that the transformer T applies to the tube a potential of contrary sign to that of the signal previously emitted and the tube N is consequently extinguished.

it may be shown that in this case it is possible to synchronize although the synchronizing torque is slightly lower than in the case Where the tube is extinguished by a signal emitted from the sending station. Of course, the action of the commutator on the tube circuit may be direct or indirect (transformers inserted with suitable local sources, amplifiers etc. not shown).

I claim:

ii. In a device for synchronizing an electric motor, the combination with an electric motor of a gas-filled tube, an oscillator circuit in which said tube is mounted, said circuit feeding current to said electric motor, means for applying a potential of brief duration to said tube to light up said tube, and means controlled by the rotation of said motor for extinguishing said tube when said brief potential ceases to be applied thereto.

2. In a device for synchronizing an electric motor, the combination with an electric motor of a gas-filled tube, an oscillator circuit fed by said tube and feeding said electric motor, means for applying to said tube a potential of brief duration to light up said tube, means for applying to said tube a potential of contrary sign to said first potential to extinguish said tube, and means controlled by the rotation ofsaid motor for controlling the instant at which said second potential is applied to said tube.

3. In a device for synchronizing an electric motor, the combination with anelectric motor of a gas-filled tube, an oscillator circuit fed by said tube and feeding said electric motor, means, including a transformer, for applying to said tube a potential of brief duration to light up said tube, an additional winding on said transformer, a source of current for energizing said additional winding, and a commutator rotated by said motor and adapted periodically to close a circuit through said. additional winding whereby a potential of contrary sign is applied to said tube to extinguish same.

4. Apparatus for maintaining the rotation 01' a rotatable body in synchronism with received synchronizing impulses comprising means for driving said body, an electric arc discharge device responsive to the received impulses for controlling the movement of said driving means and means associated with said driving means for rendering it inoperative.

RENE BAR'I'HELEMY. 

